Change Map Style

Sorry if this is a bit of a newbie question..

I want to change the landscape colour of the map because the grey blends into the background of my website too much.

I’ve got the API and the map is set up perfectly, I just can’t work out how to change the colour of it. I’ve created the map as I’d like it in the Styling Wizard but I’m stumped from there.

Any help would be greatly appreciated!

Thanks